A comparative study on the enhanced formation of methane hydrate using CM-95 and CM-100 MWCNTs

1 m(3) of methane hydrate can be decomposed into a maximum of 216 m(3) of methane gas under standard conditions. Conversely, such a large volume of methane hydrate can be utilized to store and transport a large quantity of natural gas. When methane hydrate is formed artificially by simply reversing its process of natural generation, the amount of methane gas consumed owing to hydrate formation is fairly low which would be problematic for its massive synthesis and application. In this study, experiments are carried out with the goal of increasing the amount of gas consumed by adding two kinds (CM-95 and CM-100) of multi-walled carbon nanotubes (MWCNTs) to pure water, where the physical length of CM-95 is much shorter than CM-100. When the 0.004 wt.% CM-95 MWCNT solution is compared with pure water, the gas consumption rate almost triples indicating its effect in hydrate formation. Also, the CM-95 MWCNTs decreased the hydrate formation time to a greater extent than the CM-100 MWCNTs at a low subcooling temperature. (C) 2010 Elsevier Ltd. All rights reserved.